Small to large (4-12 mm), slender flies, usually coloured brownish, greyish or blackish, sometimes yellowish or with a distinct pattern on thorax and abdomen, never metallic lustrous. Arista bare to plumose; female often with interfrontal bristles. Wing generally clear, sometimes tinged, rarely marked; venation virtually always with straight vein M1 and long anal vein. Scutellum underneath in the middle usually with a patch of fine, pale hairs. Meron devoid of bristles near hind margin.

The larvae of many genera are phytophagous, some of which are leaf miners. At the same time many species are saprophagous in diverse habitats (dung, nests of birds, etc.). Phytophagous species can be of economic importance, like various species of Delia causing damage to onions beans and other vegetables. Some species are saprophagous, or with larvae living in mushrooms or as parasitoids of insects. The larvae of Fucellia live at the coast in rotting organic matter washed up by the sea. The adults visit flowers but can be found on exuding tree sap and on dung, carrion, rotting plants, etc.